The general preparation of silver nanowires (10-200 aspect ratio) from silver ions is known. See, for example, Y. Xia, et al., Angew. Chem. Int. Ed. 2009, 48, 60, and J. Jiu, et al., Mat. Chem. & Phys., 2009, 114, 333, each of which is hereby incorporated by reference in its entirety. These include the “polyol” process, in which a silver salt is heated in a polyol (typically ethylene glycol (EG)) in the presence of polyvinylpyrrolidinone (PVP, also known as polyvinylpyrrolidone), yielding a suspension of AgNW in EG, from which the wires can be isolated and/or purified as desired.
H. Takada describes in U.S. Patent Application Publication 2009/0130433 a process for preparing metal nanowires by forming a nucleus metal particle.
Y. Sun, B. Mayers, T. Herricks, and Y. Xia (Nano Letters, 2003, 3(7), 955-960) proposed that AgNW are the result of the growth of multiply twinned particles (MTP) of silver metal.
P.-Y. Silvert et al. (J. Mater. Chem., 1996, 6(4), 573-577 and J. Mater. Chem., 1997, 7, 293-299), each of which is hereby incorporated by reference in its entirety, described the formation of colloidal silver dispersions in EG in the presence of PVP.
Previous methods of preparing silver nanowires tend to produce products with non-uniform morphologies. Such variability has been seen to increase as such methods are scaled-up.